Keratoconus (KC) is a progressive corneal ectasia and weakening with onset typically in the second decade of life. As keratoconus progresses, irreversible visual loss occurs as the result of increasing irregular corneal astigmatism, and the quality of life declines in patients.
Keratoconus is a common corneal disease and it is more prevalent in the area of West India and the Middle East which indicate a possible genetic predisposing for this condition.
The corneal stroma accounts for approximately 80% of the corneal thickness and it is usually made of highly organised collagen layers,
which contribute to the clarity of this live tissue. Recent evidence showed increased inflammatory (granular) cells in KC corneas and they may play a role in the breakdown and phagocytosis of corneal tissue, which support the inflammatory theory as a contributor to keratoconus progression. Rarely, corneal ectasia could also develop following laser refractive surgery, where the strength of the cornea has been weakened, which allows the cornea’s shape to change and become irregular.
Mild cases of KC could be treated with spectacles and observation, or collagen cross linking to stop the progression of the condition. When spectacles are not enough to improve vision, the next step is contact lenses, however not all the patients are suitable for contact lenses and they are not without side effects like causing corneal infection and scarring.
Corneal allogenic intrastomal ring segments (CAIRS) have been recently described for the treatment of KC. It is a Minimally Invasive Corneal Surgery (MICS), offering a new approach to treating corneal ectasia. These lamellar tissues (Keranatural rings) are inserted into intrastromal tunnels fashioned in the host cornea at a given optical zone to achieve a flattening effect. Unlike their synthetic counterpart plastic ring, Keranatural rings are nonrigid, pliable and they can improve the visual outcome in most cases.

If you are considering CAIRS procedure to treat your KC you must:

  • Be at least 21 year old
  • Although the aim of the surgery is to improve the vision, almost 20% of the patients would not appreciate any improvement.
  • You might still need further visual correction with glasses or contact lenses.
  • The surgery might not be suitable for severe cases with corneal scarring.
  • In severe cases of KC with significant corneal scarring.
  • Pregnant women or breast feeding.
  • Auto immune connective tissue disease.

The surgery is done under local anaesthesia with topical drops. It is as simple as a Laser Refractive Surgery. In the first part of the surgery, the Femtosecond Laser machine will form the corneal channel, and this part takes around 10-20 seconds, then the surgeon will introduce the human rings (Keranatural) inside the channel, and that part might take 2-3 minutes.

Most of the times, there would be no need for suturing and you might have a foreign body sensation for a few days.

You will be discharged home with eye drops to use for 2 weeks.

Usually, you can go back to your usual life the next day.

You will be followed closely to check for the visual outcome and to see if you need to have some fine tuning to improve the vision.

CAIRS surgery has a good chance to improve the sight in keratoconus patients. Also, it could improve tolerance to contact lenses by reducing the corneal elevation. The surgery is reversible, and if needed to, the rings can be adjusted or removed. As opposed to its plastic counterpart, there have been no reports of corneal melting or inflammation with the Keranatural rings.
  • In theory, corneal infection could happen, but this is extremely rare.
  • Needing further procedure to reposition the graft to get better visual outcome.
  • No improvement in vision.
  • Needing further surgery to improve vision.

The most important thing is to avoid rubbing the eyes as it might cause the implant to move and it could exacerbate the keratoconus.

You can take a shower 2 days after the surgery, given that you close the eye gently and do not allow water to go inside the eyes. As for swimming, it is not advisable for 1 month after surgery.

Keep in mind that the shape of the cornea might take almost 3 months to stabilise after the surgery, after which we can decide about the final visual outcome.

The CAIRS procedure cost £3200 per eye and that include the follow up visits up to 3 times with checking the progression of the visual outcome.